1. Field of the Invention
The present invention is directed to a process of cleaning semiconductor processing, handling and manufacturing equipment and wafer handling devices. More specifically, the present invention is directed to a process of cleaning semiconductor processing, handling and manufacturing equipment by contacting such equipment with liquid or supercritical carbon dioxide.
2. Background of the Prior Art
Although fabrication of semiconductor devices takes various forms, two steps, the penultimate and ultimate steps, are common to all such production. That is, all semiconductor processing steps ends with a rinsing penultimate step in which deionized water, solvents and acids are employed. The ultimate step is the removal of such water, solvents and acids. These two steps involve waste streams which must be treated, incinerated or segregated for disposal. In addition, of course, the cost of these processing fluids only add additional cost to the high disposal cost such that the combined expense of rinsing and cleaning represents a significant percentage of the total cost of producing semiconductor devices.
These problems are magnified by the requirement that semiconductor processing, handling and manufacturing equipment employed in forming semiconductor devices be similarly cleaned. That such equipment also need be scrupulously cleaned is apparent to those skilled in the art since such cleaning insures that future semiconductor devices processed, manufactured and handled by this equipment is not contaminated, and thus its effectiveness compromised, by foreign material remaining thereon.
Indeed the cleaning of semiconductor processing, handling and manufacturing equipment represents a significant environmental and economical consideration in its own right. Equipment of this type is immense compared to semiconductor devices. Oftentimes, this equipment, which is bulky, expensive and complex, must be cleaned in sequential cleaning operations employing multiple vessel cleaning configurations. As such, the quantity of cleaning fluids required is quite considerable.
It is therefore apparent to those skilled in the art that there is a significant need in the art for an improved process of cleaning semiconductor processing, handling and manufacturing equipment to reduce the significant economic charges and environmental dangers involved in cleaning such equipment.
A new process has now been developed to replace solvent rinsing and subsequent drying steps associated with the cleaning of semiconductor processing, handling and manufacturing equipment. This new process overcomes the considerable expense of utilizing solvent rinses as well as the attendent environmental difficulties associated with release of these solvents to the atmosphere.
In accordance with the present invention a process of removal of processing of semiconductor processing, handling and manufacturing equipment is provided. In this process semiconductor processing, handling and manufacturing equipment which have been contacted with semiconductor processing fluids are contacted with an equipment cleaning effective amount of liquid carbon dioxide or supercritical carbon dioxide.